In analog transmission of digital signals, there are several modulation types:
Amplitude Shift Keying (ASK)
- In ASK, the amplitude of the carrier signal is varied according to the digital information being transmitted. For example, a high amplitude might represent a binary '1' and a low amplitude might represent a binary '0'.
- ASK is relatively simple to implement but is susceptible to noise and attenuation.
Frequency Shift Keying (FSK)
- FSK changes the frequency of the carrier signal to represent different digital values. For instance, one frequency might indicate a '1' and another frequency might indicate a '0'.
- It is more resistant to noise than ASK and is commonly used in applications such as radio frequency communication.
Phase Shift Keying (PSK)
- PSK modifies the phase of the carrier signal. Different phases can represent different binary values. For example, 0 degrees phase might be a '0' and 180 degrees phase might be a '1'.
- PSK can provide more efficient transmission and is used in various digital communication systems.
These modulation techniques allow digital signals to be transmitted over analog channels, enabling a wide range of applications in telecommunications, data communication, and wireless systems.